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Quantum Computing
Quantum Computing Matthew Ham“ ' ' Computers Are Electronic Machines. The computer uses electricity, not mechanical parts, for its data processing and storage. Electricity is plentiful, moves very fast through wires, and electrical parts fail much less frequently than mechanical parts. The computer does have some mechanical parts, like its disk drive (which are often the sources for computer failures), but the internal data processing and storage is electronic, which is fast and reliable (as long as the computer is plugged in). Electricity can flow through switches: if the switch is closed, the electricity flows; if the switch is open, the electricity does not flow. To process real-world data in the computer, we need a way to represent the data in switches. Computers do this representation using a binary coding system. (Data In the Computer) ' ' Quantum Superposition In the real world, we are only familiar with traditional physics. When you throw a ball up, gravity will bring it down. However, on a quantum level, these rules that we’re so familiar with disappear. In 1926, when scientists were studying the behaviour of the electron, Erwin Schrodinger accidentally discovered one of the most important fundamentals of quantum mechanics. The electron was previously thought to orbit the nucleus. With his famous experiment, Schrodinger proved that the electron actually follows a wave pattern. That is, it’s not in any definite space; rather, it is in all of it’s possible places, based on the probability of each outcome. Therefore, the electron is in more than one location simultaneously. ' ' Schrödinger's cat is a thought experiment, sometimes described as a paradox, devised by Austrian physicist Erwin Schrödinger in 1935. It illustrates what he saw as the problem of the Copenhagen interpretation of quantum mechanics applied to everyday objects. The scenario presents a cat that is randomly put in a state where alive and dead are both possibilities, requiring further observation to determine which. The thought experiment is also often featured in theoretical discussions of the interpretations of quantum mechanics. ' ' Quantum Entanglement Measurements of physical properties such as position, momentum, spin, polarization, etc. performed on entangled particles are found to be appropriately correlated. For example, if a pair of particles is generated in such a way that their total spin is known to be zero, and one particle is found to have clockwise spin on a certain axis, then the spin of the other particle, measured on the same axis, will be found to be counterclockwise. Because of the nature of quantum measurement, however, this behavior gives rise to effects that can appear paradoxical: any measurement of a property of a particle can be seen as acting on that particle (e.g. by collapsing a number of superimposed states); and in the case of entangled particles, such action must be on the entangled system as a whole. It thus appears that one particle of an entangled pair "knows" what measurement has been performed on the other, and with what outcome, even though there is no known means for such information to be communicated between the particles, which at the time of measurement may be separated by arbitrarily large distances. ' ' Quantum Computing A quantum computer is a computation system that makes direct use of quantum-mechanical phenomena, such as superposition and entanglement, to perform operations on data. Quantum computers are different from digital computers based on transistors. Whereas digital computers require data to be encoded into binary digits (bits), each of which is always in one of two definite states (0 or 1), quantum computation uses qubits (quantum bits), which can be in superpositions of states. (Wikipedia) ' ' Applications of Quantum Computing (TIME) 1. Safer airplanes—Lockheed Martin plans to use its D-Wave to test jet software that is currently too complex for classical computers. 2. Discover distant planets—Quantum computers will be able to analyze the vast amount of data collected by telescopes and seek out Earth-like planets. 3. Win elections—Campaigners will comb through reams of marketing information to best exploit individual voter preferences. 4. Boost GDP—Hyper-personalized advertising, based on quantum computation, will stimulate consumer spending. 5. Detect cancer earlier—Computational models will help determine how diseases develop. 6. Help automobiles drive themselves—Google is using a quantum computer to design software that can distinguish cars from landmarks. 7. Reduce weather-related deaths—Precision forecasting will give people more time to take cover. 8. Cut back on travel time—Sophisticated analysis of traffic patterns in the air and on the ground will forestall bottlenecks and snarls. 9. Develop more effective drugs—By mapping amino acids,for example, or analyzing DNA-sequencing data, doctors will discover and design superior drug-based treatments. ' ' Is Quantum Computing Achievable? The current position is that simple quantum computers have been implemented with a variety of technology. Cavity QED, Ion traps, NMR are the three main methods. They have been used to make quantum computers with a few qubits, but hundreds or thousands of qubits will be required for a quantum computer which does anything useful. In 2001 researchers managed to factor 15 using a quantum computer. Not very impressive maybe, but at least it showed the field is progressing, and the more advanced uses of quantum computers might become possible. Some people though have their doubts about whether the field will progress as thought. Firstly, although error correcting codes are able to deal with the errors introduced, this is always at a cost of having to use a larger system than would otherwise have been necessary. It is hard to be sure that a working system wouldn't require so much error correcting capacity as to cancel out any computational benefit in a working system. Secondly, quantum computers require reality to match theory to very high accuracy. Although it is claimed that the theory of quantum mechanics has been shown to match experiment to whatever accuracy is required, this claim should be taken with a pinch of salt - it only applies to simple systems. The fact is that full quantum mechanical calculations simply become impossible to do with systems of any reasonable complexity. QUIZ (True or false) 1. Quantum superposition means a particle can be in two places during one point in time. 2. Commercial quantum computers will be available to the public by 2018. 3. Bits have more possible values than Quantum bits. 4. Some calculations are impossible to modern computers due to time restraint.MULTIPLE CHOICE 5. A bit can be of how many values? a)0 b)1 c)2 d)3 6. Bits use a base _____ counting system. a) 1 b) 2 c)5 d)10 7. Qubits can hold how many values at one point in time? a) one b) two c) infinite 8. Quantum coherence is achieved in: a) microscopic levels b) Large scale 9. Schrodingers experiment suggested what? a) superposition. b) Electron affinity c) Electron shells 10. Quantum computing: a) defies traditional physics b) follows newtons principles. ANSWERS: TFFTCBCAAA ' ' '' ”Bibliography ' ' Franklin, Diana, and Frederic Chong. "Challenges in Reliable Quantum Computing." Nano, Quantum and Molecular Computing. Springer US, 2004. 247-255. Print. ' ' "Quantum Computer." Wikipedia. Wikimedia Foundation. Web. 19 Dec. 2014. . ' ' Wilbraham, Antony C., and Dennis D. Staley. Chemistry. 4th ed. Menlo Park, Calif.: Addison-Wesley, 2000. Print. ' ' "Data In The Computer." Data In The Computer. Web. 19 Dec. 2014. . ' ' "Schrödinger's Cat." Wikipedia. Wikimedia Foundation. Web. 19 Dec. 2014. . ' ' "Quantum Entanglement." Wikipedia. Wikimedia Foundation. Web. 19 Dec. 2014 ' ' "9 Ways Quantum Computing Will Change Everything." Time. Time. Web. 19 Dec. 2014. "Will Quantum Computers Ever Work?" Will Quantum Computers Ever Work? Web. 19 Dec. 2014.